Runners who couldn’t complete this year’s Boston Marathon because of the bombs at the finish line have created an online petition asking organizers to let them into next year’s race.

The petition at change.org had more than 20,000 signatures on Thursday afternoon.

About 5,700 people were stopped on the course because of the explosions that killed three people and wounded hundreds more on Boylston Street on April 15. Ryan Polly, of Vermont, who was approaching the 35K checkpoint when the bombs went off, started the petition asking for runners like him to be allowed to register in the 2014 race.

Boston Athletic Association officials say they’ve heard from thousands of runners since this year’s race – on Facebook, by email and over the phone – including many who were stopped on the course. B.A.A. executive director Tom Grilk said “the common thread is one of persistence.”

“We have listened and read every e-mail and voicemail, and we have been touched,” he said. “Planning a marathon takes a lot of teamwork, and planning a marathon in the wake of the events of April 15 takes even more teamwork, communication, and planning. … As we work on our plan, and options for that group of runners which did have the opportunity to cross the finish line of the race, we ask those runners for continued patience.”